push is not always activated?

Dear All,

questions on Zimbra Mobile with Apple iPhone.

1) is there any log message when zimbra *push* emails to user's mobile devices?

2) in customer's situation, when he only configured 3 or 5 apple iPhone devices, every email will be pushed to the devices quite soon, however, when there're totally 30 devices are configured now, they found zimbra will NOT always push emails to their devices, sometimes it will, and sometimes it won't.

does anyone know how to debug such situation? any log is left when emails are pushing?

Split DNS can cause problems for iphones. By this I mean that if you have the exchange server set to a dns name, say "mail.domain.com", which resolves to your external IP address from the outside world, but to your internal IP address from your internal LAN, then push will fail quite often. The fix is to set the phone to the external IP address directly, and ensure the firewall allows port forwarding to happen from inside it's network.

This may not be your problem, it's just a guess. Have you been able to create a set of conditions that will always cause a message to be pushed and then fail. With a test case, it's easier to know what's happening.